1. Technical Field
The present invention relates to a gyro sensor, an electronic apparatus, and a moving object.
2. Related Art
In recent years, a gyro sensor (capacitance type MEMS gyro sensor element), which detects angular velocity, for example, by using a silicon micro-electro-mechanical system (MEMS) technique, has been developed. For example, JP-T-2006-515928 discloses a gyro sensor including an excitation system in which two vibrating bodies (movable structures) are connected to each other via a spring, and the vibrating bodies vibrate (also called tuning fork vibration).
In a case where such a gyro sensor is manufactured, a silicon substrate which is provided on a manufacturing base and a silicon structure which is formed by a vibrating body provided with a support spring and a connection spring, are separately prepared using a micro-processing technique such as wet etching. Next, the gyro sensor having the above-described structure may be manufactured by connecting the connection springs to each other.
However, in the above-described MEMS device manufacturing process, it is substantially difficult to manufacture the respective excitation systems in the exactly same shape. In addition, since a chemical or physical process condition cannot be maintained to be uniform at all times, even in a case where a form in which two vibrating bodies (movable structures) are connected to each other via the spring is integrally manufactured, it is substantially difficult to manufacture the respective excitation systems in shapes which are exactly the same as each other and completely symmetric to each other. Therefore, there are cases where a minute dimension error occurs in each vibrating body. When a minute difference caused by the dimension error occurs, a vibration frequency in an excitation mode is separated so as to be added to an opposite phase mode, and thus an undesirable same phase mode is formed in the natural frequency of the two vibrating bodies. Here, the term “opposite phase” indicates that two vibrating bodies move so as to become distant from or close to each other, and the term “same phase” indicates that the two vibrating bodies move in the same direction. If a frequency in an undesirable same phase mode is close to a frequency in an opposite phase mode, there is a concern that the reliability of the gyro sensor may deteriorate.